| Steps Podiatry Home Care Services Ltd | Health & social care | 2019 |
| Steve Garven Limited | Professional & scientific | 2019 |
| Stevie Kyle Ltd | Professional & scientific | 2019 |
| Stewart Mathieson Holdings Ltd | Financial services | 2020 |
| Stewart Mathieson Operations Ltd | Wholesale & retail | 2020 |
| Structure and Agency Limited | Arts & recreation | 2015 |
| STS (Ayrshire) Ltd | Construction | 2021 |
| Suilven B Limited | Health & social care | 2025 |
| Sun & Sky Inns Limited | Hospitality | 2025 |
| Sun TC Ltd | Extraterritorial | 2025 |
| Suncourt Limited | Health & social care | 2000 |
| Swiss Health Products Limited | Real estate | 1979 |
| SXA Retail Ltd | Real estate | 2019 |
| TAG Utility Solutions Ltd | Administrative & support | 2023 |
| Tartan Byte Ltd | Information & communication | 2025 |
| Taycove Limited | Real estate | 1997 |
| Technique Architecture and Design Ltd | Professional & scientific | 2019 |
| THE Aware Square Ltd | Manufacturing | 2024 |
| THE CUP and Saucer Ayrshire Limited | Hospitality | 2026 |
| THE Framework Gallery Limited | Other services | 2006 |
| THE Garden Oriental Ltd | Hospitality | 2025 |
| THE Glasgow Malt Whisky Company Limited | Wholesale & retail | 2012 |
| THE Herbary Troon Limited | Wholesale & retail | 2014 |
| THE Little Gentle Care Co Ltd | Health & social care | 2024 |
| THE Little Tykes Training Company Ltd | Arts & recreation | 2023 |
| THE Online Print Coach Ltd | Professional & scientific | 2023 |
| THE Pillar Box 2017 Ltd | Wholesale & retail | 2017 |
| THE Works Troon Ltd | Other services | 2019 |
| Thomahawk Ltd | Wholesale & retail | 2024 |
| Thomo CS Ltd | Other services | 2011 |
| Three Idiots Troon Ltd | Hospitality | 2023 |
| Tigor Properties Limited | Real estate | 2018 |
| Titan Boxes Ltd | Wholesale & retail | 2026 |
| Titan Training (Scotland) Ltd | Education | 2023 |
| TLC Property Management Limited | Real estate | 2008 |
| TNN Environmental Ltd | Professional & scientific | 2020 |
| Tooth Fairy Rich Limited | Health & social care | 2024 |
| Top One Troon Limited | Hospitality | 2026 |
| Tourer Tech Scotland Ltd | Administrative & support | 2024 |
| TRANZ4MA 22 Limited | Construction | 2019 |
| Travelsmith Golf & Leisure Limited | Transport & logistics | 2015 |
| TRN Barbers Ltd | Other services | 2025 |
| Troon Cabs Limited | Transport & logistics | 2023 |
| Troon Local Ltd | Wholesale & retail | 2025 |
| Troon Nails & Spa Ltd | Other services | 2024 |
| Troon News Limited | Wholesale & retail | 2020 |
| Troon Takeaway Ltd | Hospitality | 2026 |
| Trust Brothers Limited | Construction | 2020 |
| Tudor Life Sciences Limited | Professional & scientific | 2018 |
| Twice AS Nice Ltd | Wholesale & retail | 2023 |
| Twin Air Spray Systems (Scotland) Limited | Professional & scientific | 2018 |
| Usher Homes Limited | Administrative & support | 2020 |
| Valley Property Services Ltd | Real estate | 2003 |
| Verus HR Limited | Professional & scientific | 2006 |
| Vidhisha Limited | Construction | 2026 |
| Viscount Aviation Limited | Professional & scientific | 2014 |
| Vitale by AMY Limited | Other services | 2025 |
| Waddell & Mackintosh Solicitors Ltd | Real estate | 2018 |
| Waddell & Mackintosh Trustees Limited | Professional & scientific | 1986 |
| Wallace Hodge Trustees Ltd | Professional & scientific | 2022 |
| Waltzing Matilda Limited | Financial services | 2016 |
| Wash-A-Teria Limited | Other services | 2013 |
| Watt-Laser Technology Limited | Professional & scientific | 2022 |
| WD Scotland Limited | Administrative & support | 2014 |
| WED Holdings Ltd | Real estate | 2025 |
| WEE Hoose Developments Ltd | Real estate | 2024 |
| Weir N Property Limited | Financial services | 2018 |
| West Coast Consultants Ltd | Professional & scientific | 2017 |
| West Coast Marine Services (UK) Ltd | Manufacturing | 2012 |
| West Coast Swim School Ltd | Arts & recreation | 2021 |
| West Lodge Medical Limited | Health & social care | 2021 |
| Westsaltire Limited | Administrative & support | 2024 |
| Westward Consulting Limited | Professional & scientific | 2010 |
| WHT Consult Limited | Health & social care | 2022 |
| Wilce & Co Limited | Information & communication | 2009 |
| Willow Tree Wishes CIC | Education | 2024 |
| Winterstorm Ltd | Administrative & support | 2019 |
| World Discount Travel Limited | Administrative & support | 1999 |
| Yara Journeys Limited | Professional & scientific | 2015 |
| Yorke Advisory Ltd | Professional & scientific | 2026 |
| Young Plant Hire Ayrshire Ltd | Administrative & support | 2026 |
| Young Rail Ayrshire Ltd | Construction | 2026 |
| YR Whisky Company Limited | Manufacturing | 2023 |
| Zero NET Plastics Ltd | Manufacturing | 2024 |
| Zinc Home Accessories Ltd | Wholesale & retail | 2025 |
| Zosh Ltd | Health & social care | 2025 |